Devices of this class have been know. For example, such a device, in which an eccentric pin is displacably arranged on a body of revolution, is disclosed in West German Patent Specification No. DE-PS 38,14,927. The displacement of the eccentric pin takes place along a groove that extends at right angles to the axis of rotation of the body of revolution and through its center. A sliding block, which is connected to the eccentric pin by means of a locking screw, is slidably inserted into the groove. To adjust the distance between the eccentric pin and the axis of rotation of the body of revolution, the locking screw must be loosened, as a result of which the eccentric pin can be displaced into the desired position along the groove. The locking screw must then again be tightened, and the eccentric pin is thus again firmly connected to the body of revolution.
Even though infinitely variable adjustment of the axial displacement of the distributing rollers can be performed with this device, it is necessary to uncouple at least the drive of the body of revolution from the press drive for each adjustment process in order to stop the rotary movement of the body of revolution. Consequently, it is impossible to adjust the axial displacement of the distributing rollers during the production process with the above- described device. Consequently, the adjustment of the axial displacement requires a complicated intervention with the lifting drive. Automatic adjustment or adjustment from outside the press is not possible with this device.
Another device for adjusting the axial displacement for achieving reciprocating movement of distributing rollers is disclosed in West German Offenlegungsschrift No. DE-OS 25,14,414. A rocker arm, which can be deflected from its null position via an adjusting device, is pivotably mounted in a body of revolution. A pivot pin is fastened at its end facing away from the adjusting device. A lever, which transmits the movement to the distributing rollers via deflecting levers in the form of a reciprocating movement, is hinged to this pivot pin. Due to the rocker arm being deflected from its null position, the pivot pin is moved away to a distance from the axis of rotation of the body of revolution and is thus brought into an eccentric position.
Even though this device makes it possible to adjust the axial displacement for the reciprocating movement of the distributing rollers during the operation of the press, it might be difficult to achieve greater stroke movements as a consequence of the forces occurring as a result of load changes.
It is also desirable not only to distribute the ink by such reciprocating movement of distributing rollers during the production process, but also to use these axial displacements even during the automatic washing of the rollers of the inking and dampening system. As is known, it is possible to print with different inks over the width of the web to be printed on in printing presses that are able to print several pages side by side. To prevent two different inks of adjacent print zones from being distributed into one another and mixed with one another during the distribution by the distributing rollers, the inking rollers have recesses at the edge zones of the pages. During the printing process, the axial spreading movement of the inking rollers is smaller than the width of the recesses of the inking rollers in order to prevent a different ink from being transferred by the distributing rollers from one zone to the other. Ink will, of course, accumulate in the recesses and on the areas of the distributing roller which never extend beyond the recesses of the inking rollers during production, and this ink must be washed off at the time of a change from one ink to another or when the production is changed. In order to automatically clean the distributing rollers and the inking rollers by washing, it is necessary for the axial displacement of the reciprocating movement to be able to be increased such that it will be greater than the width of the recesses on the inking roller. In this way all the ink residues that have collected on the distributing rollers an be stripped off. To guarantee efficient automatic washing, it must be possible to adjust the axial displacement of the distributing roller even to the size of the washing stroke in a very simple manner.